Cellulosic product



June 29, 1937 R FORTUNE 2,985,463

CELLULOSIC PRODUCT Filed Feb. 2, 1935 2 Sheets-Sheet 1 Fig.2. INVENTOR.

W W BY 701916 WGQ ATTORNEYfi June 29, 1937. R FORTUNE 2,@$5,43

CELLULOSIC PRODUCT Filed Feb. 2, 1935 2 Sheets-Sheet 2 ATTORNEYJPatented June 29, 1937 UNETEB SKATES PATENT @FFIQE CELLULQSIC PRQDUCTRussell Fortune, Indianapolis, Ind.

Application February 2, 1335, Serial No. 4,720

9 Claims.

This invention relates to a new composition of matter manufactured fromnatural wood and. conforming to it in grain structure but different fromit in composition, texture and appearance.

Natural wood is a complex substance, the constituting components ofwhich have never been fully determined. It is the present theory thatnatural wood consists primarily of cellulose and lignin. The structureof the cellulose molecules and the way in which they are united are notknown. The term lignin is used, in general, to characterize the portionsof the wood other than cellulose. While this description of the natureof wood is a broad generalization which attempts to comprehend manyconflicting chemical theories as to the nature of wood, still it isadequate for the purpose of explaining this invention to the extentpermitted by the present knowledge of wood chemistry.

so Wood is used not only for many structural purposes but likewiseextensively for decorative effects which may be obtained by its use.Furniture and wood paneling are outstanding examples of the use of. woodfor this latter purpose. Nat ural Wood, however, has some very definitelimitations, both from the point of view of the interior decorator andthe furniture manufacturer. In the first place, the color of any givenpiece of wood is the result of theoperation of nature and varies withthe specie of tree, its age, the soil in which it grew, climaticconditions which provailed during its growth, and the portion of thetree from which it was out. It has been conventional, to stain woodsvariously but in each case the original color of the natural wood hasimposed a limitation on the color range to which .it could be stained.Also, from the pointof view of the manufacturer, it has always beendiflicult to match woods so that supplying additional pieces orreplacing pieces in a given furniture suite was possible.

Of late, there has been a decided trend toward painted wood because thelatter inherently avoids the limitations of natural wood as to color.The painting ofwood, however, sacrifices its greatest feature of naturalbeauty, the inherent pattern or figure. Modern interior decorationrequires greater latitude and delicacy of color than is possible innatural wood and on this account attempts have been made to substitutesynthetic resins or metal products for wood, in 'furniture, paneling,and the like. However, products of this nature are cold, hard andlacking in natural beauty so that interiors done in these newer maentfrom ordinary wood in appearance, and ap- Otherwise expressed, theprodpeal to the eye. ucts of this invention comprise the cellulosiocomponents of natural wood disposed in relation to one another as bynature, but substantially divested of pigmented lignin. The term"pigmented lignin is used herein to describe natural colors occurring inthe wood, whether they be actual components of the lignin itself ordyestufis of nature deposited in the wood. The pig= mentation of wood isno better understood than the chemistry of the lignin (concerning whichlittle is known), and, moreover, the nature of the pigmentation seems tovary from one specie of wood to another. However, the products of thisinvention may be made from a great variety of woods including oak,maple, beech, aspen, mahogany, ash, koa, Oriental wood, red wood,bubinga, poplar, American walnut, madrone, Oriental sillswood, silkyoak, and other woods native to various parts of the world. In all casesthe products of this invention are characterized by the sub.- stantialabsence of pigmented lignin, an ab- .sence which imparts acharacteristic sheen to the cellulosic structure and paves the way forany desired artificial pigmentation. Therefore, the terminology naturalwood cellulosic structure substantially divested of pigmented lignin isintended to comprehend not only wood products curately determined, it isimpossible to describe the products of this invention as compositions ofmatter except in relation to the properties of the natural wood fromwhich the products are defrom the natural wood from which they are madeby absence of the characteristic color of the original wood, a lustroussurface, lesser specific gravity, greater permeability and absorbingcapacity, and an optical effect which is impossible to describeadequately or to reproduce fully by drawing or photograph.

Natural wood is characterized by the fact that it is differentiallypigmented, these differences of pigmentation dominating the visualeffect commonly called the wood pattern. If a sample of almost anyvariety of wood be examined carefully, it will be observed thatthepattern is primarily'constituted by variations of color ranging froma light brown or yellow through darker browns to black, the particularrange in each case being determined by the nature of the wood. Manyvarieties are of reddish tone or vary from red to red-brown. Theproducts of this invention, on the contrary, are usually a substantialmonotone as to color. ,However, the character of the wood, particularlyif it be pronounced, stands out by virtue of variations in the fibrestructure of the wood which causes certain portions of the surface toreflect and absorb light difierently. While difierent-ial lightreflection and absorption exists in natural wood, this factor issubordinated from the point of view of appearance by the colorintonation. When this latter factor is removed, the appearance of thewood is dominated by the variegations of the relatively light reflectiveand absorbent areas.

- While it is difficult to offer complete and adequate explanation ofthe difierence between the appearance of the wood products of thisinvention and natural wood, particularly the aesthetic efiect, stillcertain definite changes in light reflectivity have been noted and arementioned as proffer and partial explanation.

The wood products of this invention (unless light reflection than theoriginal wood from which they' are made. As a result the pattern of thewood may provide greater contrasts of reflectionand absorption than ispossible when the coeflicient of reflection-is lower. On this account,the pattern of the wood in many specimens stands out very strikingly tothe eye. This increase in the coemcient of reflection takes gplace, to asubf-i stantial extent, in the green tofiilow chromatic wave lengths,the range to which the retina of the eye is most sensitive. Therefore,the wood products of this invention, while characteristically woodlikebecause of the accentuation of the wood pattern, still have acharacteristic appearance of their own due to their relatively highcoeflicient of reflection in the chromatic range to which the eye ismost sensitive. On this account the products appear live, interesting,scintillating or stimulating in comparison with the more subduedappearance of natural wood.

The use of any great amount of natural wood in interior decoration,whether in paneling or in heavy furniture, produces an efiect which issombre, dignified and, in some cases, actually depressing. On thisaccount natural wood has for practically any type of interiordecoration,

but are particularly suitable for more gay, lively and colorful schemesof decoration.

The products, when not artificially colored,

have a sheen and luster akin to that of mercerized cotton, rayon orsatin, and whether the 'effect be due to a more translucent nature ofthe surface or the greater coefficient of reflection in the color rangesto which the eye is particularly sensitive, still the fact remains thatthe surfaces are more arresting and interesting to the eye than ordinarywood surfaces. Even if these surfaces be artificially colored, thislastspecified property of the surfaces is not lost but is, in some cases,actually increased so that whether the surfaces be white, green or blackin actual color, they have a certain aesthetic property in common whichdifferentiates them from natural wood.

Unless artificially pigmented, the wood product of this invention ismore translucent than the material from which it was made and on thisaccount the surface has the appearance of greater depth. The differencebetween the transparency or translucency of the products of thisvinvention and corresponding properties of natural wood are accentuatedif thin sections be soaked in water. In the case of natural wood, thetransparency or translucency is not materially affected, whereas theproducts of this invention transmit light to a very marked degree whenwet .out with water. With many varieties of wood, bewildering lighteffects take place at the surface which cannot be artificially colored)have a higher coefficient of accurately described. For instance, a givenportion of the wood appears white when light is reflected from it on oneangle, and pale yellow or gold from another angle. On some specimens thegrain seems to stand out in white and cream in a given light, but onchanging the angle of light the design reverses and the portions whichseemed cream become white, and vice versa.

With many varieties of wood, for example, maple,

the pattern may appear in light and shadow, an effect which the eyeinterprets as relief. In fact it is diflicult to believe'some samplesare smooth at the surface, except by touching them.

It must be understood throughout this description that the color effectsare described from the point of view of an observer, not from the pointof view of spectral analysis. By variations in the length of treatmentdifierent spectral color readings may be obtained, or by artificialpigmentation various colors are produced, but in all cases the naturalcolor of the wood is substantially nullified so that the finishedproduct without artificial coloration bears no color resemblanceto thenatural product from which it was made, or with artificial colorationdoes not resemble the natural product with similar artificial color-'-ation.

Since this invention provides a product characterized by the pattern ofthe natural wood of a color to the taste of the designer or decorator,-

the invention has application to the veneer field. At the present timecabinet, work and paneling is fabricated with veneers because veneerpanels are stronger and have less tendency to warp or check than singlethickness panels, and also it. is possible to obtain more artisticeffects from veneers because of the facility with which wood mine.

patterns may be matched or related. Veneers, in general, are thin sheetsof wood ranging roughly from one-eighth to one-onehundredth of an inchin thickness. Obviously, veneers may be made thicker but such a practicewould utilize more of the expensive wood and serve no useful purpose atthe present stage of development of the veneer art. Veneer may be madeup into veneer panels with other layers of wood (laminated structure) ormay be attached under pressure to a solid piece of wood or core. Othertypes of backing for the veneer may, of course, be employed such ascanvas, sheet metal composition materials, synthetic resins or the like,although attachment of the veneer to a wooden backing is more common atthe present time.

The veneers of this invention are preferably one-eighth toone-onehundredth of an inch in thickness and substantially uniform incomposition throughout. This latter feature precludes the possibility ofmigration of pigmented lignin within the cellulosic structure. Theincreased porosity or permeability of the veneer of this inventionfacilitates its attachment to the 'core or backing and thereby providesa veneer product of greater strength and durability than thosepreviously available. This feature likewise makes possible the use notonly of stains normally employed for natural wood, but likewise specialfinishes or impregnating treatments which may be desirable either tomodify color or to modify the textural appearance. The veneer product ofthis invention is, therefore, superior to natural veneers, both from thepoint of view of the manufacturer endeavoring to do good, lasting veneerwork, and from the point of view of the designer attempting to achieveunusual or artistic efiects.

The veneers of this invention are thin parchment-like products, limpwhen wet, hard when dry, in most cases less brittle than the corresponding natural veneer, and of equal or superior toughness. Thespecific gravity of the veneers of this invention is usually about 2 to25% less than the corresponding veneers of equal thickness from naturalwood, though loss of .weight depends in each caseupon the nature of thewood and the degree of the treatment.

It is recommended that the veneers of this invention be of substantiallyuniform color and texture throughout, that is, relatively homogeneousproducts. This provides-a product which may be sanded or finished tovarying depths without a1- teration of visual characteristics.

The exact nature of the components removed from the wood by thetreatment is a matter of speculation. Since the cellulosic structureseems to be structurally intact save for a slight shrink age orcontraction, it would seem that a portion of the lignin is absent.Whether or not the lus-- trous appearance of the surface is accountedfor by lignin removal or chemical change of the cellulose and/or ligninin the nature of hydrolysis, oxidation or chlorination, is impossible todeter- It appears that the products of this invention are intermediatenatural wood and paper, the cellulosic structure ,or grain structureconforming to that of natural wood, the color and texture approachingthat of paper.

The veneers of this invention may be constituted by the mild applicationof incipient paper making chemical processes which remove ligneous colorphysically and/or chemically without disrupting the cellulosicstructure. The components of the wood which are modified and/or removedare those which are soluble in a. dilute and the relatively aqueoussolution, the constituting components of which are chlorine gas and analkali. Various chemicals may, of course, be combined to provide asolution chemically equivalent to the one described. One solution whichhas been found suitable for making veneer products of this in-= -ventionis constituted by 100 gallons of water,

5 pounds chlorine gas, pounds technical caustic soda (76%), 37.5 poundssoda ash (58%).

The natural veneer sheets are treated in a bath of this solution over aperiod of from 4 to 72 hours, the exact length of treatment dependingupon the type of wood being treated, its thickness, the ratio of squarefootage of wood to quantity of solution, and the precise nature of theproduct desired. For instance, as an example, I have treated mapleveneer, one-twentysixth of an inch. in thickness, of a type known in thetrade as Oregon blistered maple, in a bath of this composition foreighteen hours and obtained a remarkably white, lustrous veneer product.In this treatment, square feet of this veneer were used to 100 gallonsof solution.

In all cases, a low temperature, such as 129 F., is recommended fordrying, though with specialized equipment higher temperatures may beemployed.

In the accompanying drawings I have attempted to illustrate my inventionas fully as possible.

Figure 1 is a photographic reproduction of a panel faced with naturalHawaiian koa veneer. The veneer was obtained from a half-round cut fromstump wood.

Figure 2 is a photographic reproduction of a panel faced with a productof my invention made from successive sheets from the same fiitch ofHawaiian koa with which the panel shown in l was faced. This veneer wastreated in a solution similar to that described in the foregoing examplefor approximately forty hours, fifty feet of the natural wood beingtreated in 100 gallons of solution.

Figure 3 is a photographic reproduction of a panel faced with'a productof my invention treated similarly to the product shown in Figure 2 butadditionally soaked in a 10% solution of copper sulfate for a period ofapproximately twelve hours.

Figure 4 is a photographic reproduction of a panel faced with a productof my invention made from American maple cut from a tree having a curlygrain. This product was obtained by treating the natural veneer in asolution similar to that described in the foregoing example for a periodof twenty-eight hours, sixty feet of the natural Wood being treated in100 gallons of solution.

Referring to Figure 1 it will be noted that the natural veneer of theHawaiian koa of the example is characterized by substantially longi--tudinal streaks, which in natural color usually n. The panel shown inFigure 2, faced with a prcduct of my ingention made from sheetssuccessive in the flitcfi-to those sheets used to face the panel showhin Figure i, may be characterized by a differently appearing texture andby transverse grain pattern. The longitudinal markings appearing inthepanel facing reproduced as Figure 1 are relatively imperceptibleimperceptible transverse markings of the facing in 1 appear to dominateor characterize thisproduct of my invention,

Since white furniture is very much in vogue at the present time andsince the relatively white wood or veneer constitutes a starting pointfrom which a variety of artificially colored woods may be made, theappended claims are directed generically to the new composition ofmatter of this invention, regardless of color, and specificaily to a[colorless wood product. Claims directed to a preferred process ofde-colorizing wood appear in my copending application, Serial No.123,555.

Having describedmy invention, I desire to be limited only by the ensuingclaims:

1. As a new article of manufacture, a sheet of facing veneerstructurally intact but of reduced lignin content and devoid of colorintonation.

2. A treated veneer product produced from commercial veneer from which aportion of the lignin has been removed, and also characterized by visualaccentuation of the original fibre structure and organization on asubstantially colorless background having a lusterized surface.

3. A flat and lustrous veneer product produced from commercialveneer'but retaining the original fibre structure and characterconfiguration, said product being relatively de-pigmentized, slightlyshrunk, characterized by increased activity of water absorption, andhaving the property of uniformly receiving coloring matter.

4. A substantially colorless chemically treated veneer from which aportion of the lignin has been removed, and which, compared to untreatedveneer, exhibits retained original fibre structure components of thepattern and increased activity of water-absorption.

5. A veneer surface produced from commercial veneer, said product beingfree of synthetic coloring matter, characterized by disappearance ofcoloring matter, visible accentuation of the pattern on a background ofuniform tone, said veneer surface being lustrous and having an increasedcoefiicient of light reflection with respect to the natural wood fromwhich the veneer was constituted.

6. A sheet of veneer produced from a commercial face veneer from whicha. portion of the lignin has been removed, characterized by visualaccentuation of the original fibre structure and organization, having alustrous surface and being of substantially uniform composition, textureand color in cross section.

. 7. As a new article of manufacture, a piece of wood structurallyintact as to fibre arrangement as compared to naturalwood,.substantially devoid of color intonation throughout, having" alignin content lesser in amount than natural 4 wood, and bearingartificial coloration throughadhesive, said facing comprising acellulosic-derivative of natural .wood exhibiting the fibre but devoidof the natural color of natural wood.

9. A fiat lustrous veneer facing produced from commercial veneer,retaining and exhibiting undisturbed fibre orientation and inherentpattern and having a fibre structure in which the natural pigmentationis replaced by artificial coloration throughout.

RUSSELL FORTUNE.

